Coring apparatus



J. C. STOKES CORI Nov. 13, 1951 MG APPARATUS Filed Dec.

ATTORNEYS Patented Nov. 13, 1951 comivc APPARATUS .John C. Stokes,Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., acorpora tion of Texas Application December13, 1948, Serial No. 64,924

Claims. 1

This invention relates to new and useful improvements in coringapparatus and more particularly to improved means for mounting the innercore-receiving barrel of such apparatus.

In the conventional core-taking apparatus of the type wherein an innercore-receiving barrel is carried within an outer barrel and is run intothe well bore with the drill stem, it is customary to mount the innercore-receiving barrel so that it is freely rotatable within the outerbarrel during the coring operations. It is, of course, desir-, able thatthe core barrel be mounted in a bearing assembly which will not onlypermit free rotation but which will also take the longitudinal or endthrust to which the inner core barrel may be subjected. Various methodsand means of mounting the inner core barrels are in general use but inall such arrangements in which the bearings function as upper and lowerend thrust bearings, it has been necessary to locate the bearingassembly at the upper end of the core barrel at a spaced distance fromthe core bit. Because of this loca-, tion of the bearing assembly, thecore barrel must be removed from the upper end of the apparatus, therebyrequiring that the connection betweenv the apparatus and the drill pinebe broken. Further, with the bearing assembly at the upper end: of theinner core barrel, the core barrel must be fitted with relatively closetolerances between the said bearing assembly and the core bit at thelower end of the apparatus, thereby complicating the structure andincreasing the expense of manufacture.

It is, therefore, one object of this invention to provide an improvedmounting for the inner core barrel of a core-taking apparatus whereinthe supporting bearing assembly is disposed nearer the lower end of thecore barrel, whereby the necessity for the close manufacturingtolerances heretofore required is eliminated and also whereby the corebarrel may be readily removed from the apparatus by merely removing thecore drill and without having to break the upper connec-v tion.

An important object of the invention i to provide an improved mountingfor the inner corereceiving barrel of a core-taking apparatus whichmounting includes a double set of ball bearings located at the lowerportion of the barrel for rotatably supporting the barrel and for takinglongitudinal end thrust, the upper end of said barrel being aligned by asimple aligning bearing mem-.

an improved apparatus, of the character described, wherein the doubleball bearing assembly on which the core barrel is rotatably supported isconfined within a bearing housing, with said housing being disposedwithin the lower portion of the core-taking apparatus adjacent the corebit, whereby disconnection of the bit allows the, core barrel to bereadily removed from the outer barrel of said apparatus.

Still another object of the invention is to provide an improved bearingassembly for mounting an inner core-barrel within the outer barrel of a.

core-taking apparatus, said assembly including upper and lower ballbearings and having suitable packing means for sealing off at the endsof the bearing assembly, together with simplified means for mountingsaid assembly against upward and downward displacement within theapparatus.

Other objects and advantages more or less ancillary to the foregoing andthe manner in which all the various objects are attained will appear inthe following description, which considered in connection with theaccompanying drawings, sets forth the preferred embodiment of theinvention.

In the drawings: v 1

Figure 1 is a longitudinal sectional View of a core-taking apparatus,constructed in accordance with the invention,

Figure 2 is an enlarged longitudinal sectional view of the lower portionof the apparatus and showing the improved mounting for the innercorebarrel, and V Figure 3 is a horizontal cross-sectional view taken on theline 33 of Figure 2.

In the drawings, the numeral l0 designates the lower portion of a drillpipe which has a sub ll connected to its lower end. The core-takingapparatus is connected to the .drill pipe through the.

the sub. The lower end of the barrel I2 is con-- nected within the upperend of a drill collar l3,

and this connection is also illustrated as a weld,. although if desiredit may be threaded. The.

lower end of the drill collar I3 is formed with the usual threaded pinl4, whereby a core bit l5 may be connected thereto. It will be evidentthat upon rotation of the drill pipe in, the outer barrel l2, drillcollar [3 and core bit l5 will be rotated.

The core bit IEmay be of any desired construetion and, as shown in Fig.2, has a central or.

axial bore l6 which bore is reduced at its lower portion, as indicatedat l5a,'whereby an internal 3 shoulder I! is formed within the bit.Suitable cutters l8 are mounted on the lower portion of the bit andvertical fluid passages I9, which extend through the body of said bit,direct fluid onto said cutters during the coring operation. A corecatcher 2B, which may be of ordinary construction, is supported upon theinternal shoulder l1 within the: bore= of the. bit, and includes pivoted.fingers 2! which are normally urged inwardly into the bore. The body ofthe core catcher is generally sleeve-like and has its upper portionreduced, as indicated at 20a, whereby,

the exterior surface of the core catcher body is spaced from the bore [6ofrthe: corabit. body I:

A suitable protector sleeve 22- -is,-.1nitially. suspended within thebore of the bit and is prevented from upward movementthrough the.bit. bymeans of projections 23 on its external surface. The body of theprotector is :provided, with slits 24 and when a sufficient force isexerted against the lower end of. the. protector, the projections 23-may. flex inwardly, thereby permitting the protector to'move upwardlywithin the bit. Downward movement of the protector 22 is prevented bythe engagement of. the core catcher fingers 2|. with annular grooves ornotches.25 formed in said. protector. The protector 22, aswell asthecore. catcher. 2!!- and the core bit l5, are all parts or usualconstruction,

and. the particular details thereof are subject to variation.

An inner core-receiving barrel. 26-extends axially within the outerbarrel l2. and also within the drill collar l 3. and has its lowerendterminatingadjacentthe upper. endof the core catcher 20. The upper.end of the. barrel is closed. by avalve cage21 whichis threaded. intothis upper portion and. a suitable ball check valve 28. is mountedwithinthe cage. The valve cage or body 2.1.is formed in two. pieceswhich are connected by a. threaded connection, and. an. annularalignment-bearing. 29. is mounted. within an annular groove. 30 formed.inthe upper end oithe valve. cage. or body 21.. .The alignmentbearing.may be constructed of neoprene or other. suitable material and has itsouter peripheral surface formed with ribs or ,enlargementswhich areadapted to abut the bore l2a, of'the outer barrel l2. The alignmentmember 29 functions to axially align the upper end .of the inner barrel26 within the outer barrel 12, while permitting a downward flow of fluidthrough the annularspace between said barrels. The valve cage. or body21 has an axial .bore 21a which communicates with the area adjacent thevalve seat 28a,

which is engaged .by the ball valve 28. A vent tube 32 threads into thebore 2.1a and extends upwardly therefrom.

It will be apparent that the ball valve 28 is downwardly closing andwill prevent the admission of any fluid which may be flowing downwardlythrough the drill pipe into the core-receiving barrel 26. However, thepressure. within the core barrel 26 exceeds the pressure acting againsttheupper end of the ball valve 28, said valve may be unseated to permita venting of the upper end of the barrel.

For rotatably supporting the lower portion of the inner barrel 26, .saidinner barrel is provided with an external annular flange 33 which may beformed integral with said barrel. The flange 33 is located nearer thelowerportion of the barrel 26 and its upper surface provides an upper,bearing. raceway 34 while its lower surface forms a lower bearingraceway 35. Upper .32

rbetween the barrel 26 and the housing 38.

The lower portion of the bearing housing 38 telescopes and is suitablysecured to the upper end of atubular, sleeve or casing 42. The upperendiof this'casing or sleeve has the lower bearings 31: supported:thereon, whereby this upper .edge, indicated at 4211, forms a racewayfor the "lower ball" bearings 31.

The sleeve or casing 42 extends. downwardly and has its lower endinsertable within the bore; l6 of the core bit. An external annularshoulder 43 which is. downwardly facing,v is formed on the lowerportion. of. the sleeve or casing 42 and abuts an internal shoulder l5aprovided within the core bit, the engagement of the external shoulder 43with the internalshoulder l5a functioning to limit the downward movementof the sleeve or casing 42. For confining the bearingassembly against.upward. movement with respect to the core, bit and outer barrel, aplurality of spacing ribs, 4.4 are welded. or otherwise secured. to theintermediate portion. of the sleeveor casing .42. Each ribis. formedwith an upwardly facing shoulder 45. at its lower end, and thisshoulder. is adapted to abut the. Thus, it will.

lower end l3a of the drill collar I3. be seen that when the inner barrel26 and, its lower bearing assembly are in position within the. outerbarrel and vdrill3collar, said inner barrel and bearing assembly isconfined against upward:

'bit. It is noted that the spacing ribs 44 also function to axiallyalign the lower portion of the bearing assembly sleeve 42 within thedrill collar, and thus, the lower end of the core-receiving barrel 26 isaxially aligned with respect to the outer barrel I2.

In use, the apparatus is assembled as shown in Figure 1 with the innercore-receiving barrel 26 supported upon the double set of ball bearings36 and 31 at its lower portion. The upper end of the core-receivingbarrel 26 is maintained in axial alignment within the outer barrel I2 bythe annular alignment bearing member 23. As the coring operation iscarried out by rotating the drill pipe, outer barrel I2 and core bit l5,the core which, is cut ,moves upwardly within the bore of the innerbarrel 26. The inner barrel, being mounted on the upper and lowerbearings 36 and31, may remain stationary, While the outer barrel andcore bit rotate. The bearing assembly sleeve 42 has its lower endengaged within the bore of the core bitandthis sleeve will, rotate withthe bit. As is clearly shown in Figure 2, the bearing assembly sleeve 42and the confining bearing housing 38, which is attached to said sleeve,are rotated with thecore bit and outer barrel. The inner core-receivingbarrel 26 remains stationary because of its engagement with the core,and free rotation of the bearing assembly housing and sleeve is possiblebecause of the double ball bearings 38 and 31. Any end thrust whichmight occur longitudinally of the inner barrel 26 is taken by thebearings 36 and 31, upward thrusts being absorbed by the upper bearings36 with the downward thrust being upon a the lower bearings 31.

After a core has been taken, it is only necessary to disconnect the corebit I from the drill collar l3. As the bit is removed, the lower portionof the bearing assembly sleeve 42 is disengaged from the bore l6 of saidbit. The entire inner barrel 26, together with the lower bearingassembly, may then be removed through the lower end of the barrel l2 andits drill collar l3. Removal of the barrel 26 results in a removal ofthe check valve arrangement 28 as well as the vent tube 32 which aresecured to the upper end of said inner barrel. Thus, it is possible toretrieve the core without having to break the connection between thedrill pipe and the outer barrel l2 at the upper end of said outerbarrel. Furthermore, since the main bearing support is at the lower endof the inner barrel 26 and the upper end of said barrel is maintained inaxial alignment by a simple annular bearing element, close tolerances inarranging the bearings are not necessary. As illustrated, there may be asubstantial distance between the upper end of the valve cage 27 and thelower end of the connecting sub II. In prior devices, where the doublebearing assembly is located at the upper end, the lower end of thebarrel must be supported within the core bit and the tolerances must beheld fairly close. In the present arrangement, wide tolerances areallowed which simplify manufacturing and reduce costs.

The particular bearing assembly is extremely simple and provides notonly for free rotation of the inner barrel with respect to the core bitand outer barrel, but also functions to take care of any longitudinalend thrust in any direction. The bearing housing 38 may be provided witha suitable fitting 41 which would permit lubricant to be directed to thebearings 36 and 31. If desired, the supporting sleeve or casing 42' ofthe assembly may have a radial port or ports 48 extending through itswall, whereby the drilling fluid or mud which is circulated downwardlybetween the inner barrel 26 and the outer barrel I2 during the coringoperation may enter the interior of the sleeve or casing 42 and functionto lubricate the various parts. The bearing assembly and the lower endof the core-receiving barrel 26 are actually supported within the corebit [5 and upward displacement of the parts is prevented by the externalshoulders '45 of the spacing ribs 44 which are secured to the exteriorsurface of the bearing assembly; This makes it possible to readilyinsert or remove the inner core-receiving barrel 26 by merely removingthe core bit l5. J

Having described the invention, I claim:

1. In a coring apparatus, an outer barrel, a core bit threaded onto thelower end of said barrel, an inner core-receiving barrel extendingaxially within the barrel, and a bearing assembly supported within thecore bit and including an elongate sleeve extending upwardly andencircling the lower portion of the inner barrel,

bearing means between the sleeve and inner barrel for rotatablysuspending said inner barrel within the outer barrel, and means forsealing the space between the sleeve and barrel above the bearing meansto protect the bearing means from contact with fluid circulatingdownwardly around the exterior of the inner barrel.

, 2; In a coring apparatus, an outer barrel, a core bit threaded ontothe lower end of said barrel, an inner core-receiving barrel extendingaxially within the barrel, and a bearing assembly supported within thecore bit and attached to the core-receiving barrel, said bearingassembly extending upwardly to encircle the lower portion of the innerbarrel and having means for rotatably suspending said inner barrelwithin the outer barrel, means within the core bit engageable by thelower portion of the bearing assembly for supporting the assembly andinner barrel, whereby disconnection of the bit from the outer barreldisengages said bit from the lower portion of the assembly,and saidassembly and the inner core barrel may be subsequently removed as a unitfrom the outer barrel through the lower end thereof.

3. A coring apparatus including, an outer tubular barrel, a core bitconnected to the lower end of the barrel, an inner core-receiving barrelextending axially within the outer barrel and having an annularprojection on its lower portion, a bearing assembly including a tubularmember surrounding the lower portion of the inner barrel and alsoincluding upper and lower bearing elements within the bore of thetubular member engaging opposite sides of the annular projection,whereby the inner barrel is rotatably suspended on said bearingelements, and means at the lower end of the bearing assembly forengaging the core bit to support said assembly.

4. A coring apparatus including, an outer tubular barrel, a core bitconnected to the lower end of the barrel, an inner core-receiving barrelextending axially within the outer barrel, an external annularprojection on the lower portion of the inner barrel and having its upperand lower surfaces forming bearing raceways, bearing elements on saidraceways, and a confining housing surrounding the inner barrel andconfining said bearing elements on their respective raceways, means formounting the housing against displacement from the inner barrel, andmeans for supporting the housing within the outer barrel, whereby theinner barrel is rotatably suspended within the outer barrel by means ofsaid bearing elements and housing.

5. A coring apparatus including, an outer tubular barrel, a core bitconnected to the lower end of the barrel, an inner core-receiving barrelextending axially within the outer barrel, an external annularprojection on the lower portion of the inner barrel and having its upperand lower surfaces forming bearing raceways, bearing elements on saidraceways, a confining housing surrounding the inner barrel and confiningsaid bearing elements on their respective raceways, means for mountingthe housing against displacement from the inner barrel, and means forsupporting the housing within the outer barrel, whereby the inner barrelis rotatably suspended within the outer barrel by means of said bearingelements and housing, and an aligning means carried by the upper portionof the inner core-receiving barrel for maintaining the inner barrel inaxial alignment within the outer barrel.

6. A coring apparatus as set forth in claim 2,

7 weat w th h a in Me n at he up r 29 tion of the inner core-receivingbarrel for axially aligning said inner barrel Within the-outer barrel.

'7. A coring apparatusas set forth in claim 4, wherein the means forsupporting the housing within the outer barrel comprises an internalshoulder within the core bit engageable by the lower end of the housing,and also wherein said housing is formed. with an external projectionwhich engages the lower portion of the drill Stem for limiting upwarddisplacement of saidhousing relative to the drill stem to thereby limitupward axial movement of the inner barrel relative to theouter barrel.

8. A coring apparatus as set forth in claim 4, together with a packinmeans interposed b e-v tween bearing housing and the inner core barrelfor packing off between these parts above the bearing elements.

9. A coring apparatus as set forth in claim 4, wherein the supportingmeans for the bearing housing comprises an external shoulder at itslower portion which is adapted to engage and rest upon an internalshoulder in the core bit, where? by when the bit is disconnected fromthe outer barrel its external shoulder disengages the hearing housingand said housing and inner barrel may be removed as a unit from theouterbarrel through thelower end of said outer barrel.

1 0 A coring apparatus includjng, a drill stem,

8; a core'bit connected to thelower end of theidrill stem, acore-receiving. :barrelmounted axially within the lower portion of thedrill stem, a hear-.- ing assembly surrounding the lower portion of thecore receiving barrel-for rotatably supporting the lower end. of thecore barrel, means mounting the bearing assembly against displacementfrom the core-receiving barrel, means on the core bit engaging the lowerbearing assembl to maintain JOHN C. STOKES.

" REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,305,727 mith-.-4-.V---,.---:--V M 3i 1 345,23 B ow F b: 93

8 5 2 'S uermen f fe- Au 1932

